Up to 40 U.S. soldiers streamed out of a CH-47 Chinook in an air assault on a Taliban position in southern Afghanistan shortly before the helicopter crashed, officials said Thursday. Five Americans, a Briton and a Canadian were killed.

The Chinook's plunge late Wednesday came on the first day of a new joint NATO-Afghan operation to force Taliban fighters out of the northern part of Helmand province.

NATO said troops who went to the crash site were ambushed by enemy fighters, and the unit called in an airstrike. The U.S. military said "a large number of insurgents" were killed.

Maj. John Thomas, a spokesman for NATO's International Security Assistance Force, said the Chinook - a heavy lift twin rotor helicopter - had just dropped off a full load of troops from the 82nd Airborne before it went down. He said between 30 and 40 troops would likely have been on board.

"It was a hostile area, where the helicopter went down," said Thomas.

Thomas said initial indications were that enemy fire may have brought down the Chinook, and a U.S. military official, who insisted on speaking anonymously because the crash was under investigation, said reports suggested the helicopter was hit with a rocket-propelled grenade.

The Taliban claimed responsibility for attacking the aircraft.

But Lt. Col. David Accetta, the top U.S. military spokesman at Bagram Air Base, said enemy fire was only one of several possibilities.

"We will investigate thoroughly," he said. "There's no solid evidence we can point to that suggests it was shot down."

It wasn't clear how many minutes after the helicopter dropped off the U.S. troops the helicopter crashed, Accetta said.

The troops wouldn't have landed on "a hot landing zone" - a spot full of Taliban forces, he said. But troops would have landed within range of enemy fighters so that the ISAF forces could attack them.

The U.S. soldiers and the Briton killed have not been identified. The Canadian soldier was identified as Master Cpl. Darrell Priede, a combat cameraman.

Helicopter crashes in Afghanistan have been relatively rare. A Chinook crashed in February in the southern province of Zabul, killing eight U.S. personnel. Officials ruled out enemy fire as the cause.

In May 2006, another Chinook crashed attempting a nighttime landing on a small mountaintop in eastern Kunar province, killing 10 U.S. soldiers.

In 2005, a U.S. helicopter crashed in Kunar, after apparently being hit by an RPG, killing 16 Americans.

Some 2,000 ISAF and Afghan forces are taking part in the new operation, Britain's Ministry of Defense said. The offensive includes forces from Britain, the U.S., Denmark and Estonia.

Lt. Col. Charlie Mayo, a British military spokesman, said the continued presence of Taliban fighters in the upper Sangin Valley was putting at risk previous "good work" done in Helmand, the world's largest opium poppy-growing region and a Taliban stronghold.

"This is certainly not a major fresh offensive but a continuation of the progress made by NATO's Operation Achilles launched in March," Mayo said.

In fighting elsewhere, Taliban militants ambushed a police convoy in Shahjoi district of southeastern Zabul province on Wednesday, starting a gunbattle that left 16 police and 10 suspected insurgents dead, Interior Ministry spokesman Zemeri Bashary said. Six police were wounded.

On Thursday, Afghan and NATO forces battled suspected Taliban in Helmand's Sangin district. The Defense Ministry said "tens of enemies" were killed or wounded in clashes and airstrikes, but did not provide further detail.

After a winter lull in violence, both militant attacks and military operations have escalated this spring.

More than 1,800 people have died in insurgency-related violence this year, according to an Associated Press tally based on figures from U.S., NATO and Afghan officials.

Regards

John

"You rise,you fall, you're down then you rise again
What don't kill you make you more strong"